Flash-light composition.



' STATES PAT T O CARL Barnes, or BERLIN, GERMANY.

amen-Lion's comosrriox.

No. siesta, 'i I Toallwhmnitm a/ycoucem:

I 1 Be it known that I, CARL Bn'rnen, a subject of the of Prussia, German Emror, and resident of 18 Schlesischestrasse,

erlin, Kingdom of Prussia, German Em-' pire,. --have invented a 'new" and Improved F lash-Light Composition, of which thefollowing is an exact specification.

The present invention relates to the production of a mixture for producing flash lights or time-lights with high actinic properties for photographic and like'purposes'.

Thev novelty of the present invention con sists in mixing. the known combustible metals, suchas magnesium, aluminumand the metals 'of the alkaline earths with compounds composed of thorium and acids vof the heavy metals. Peroxid of thorium with an acid may also be emplo'yed with equally good efi'ect. p

Compounds ofthe.rare-.,eartlis have a1;

' ready beeiremployed as the oxygencarrier in .the production of fla sh light mixtures \vhichjcpmpounds as is'knbwnar'e distin guished-by their strong lighting properties,

thus nitrates and sulfates havchitherto been proposed. The nitrates however have'not only a strong acid action but are also very hygroscopic and in consequence mixt of these nitrates'with magnesium pow r do notpreserve their active properties. when preserving the ingredients separately as powders, as is usual for transport'purposes, the pulverized nitrates after a short time form into balls in consequence of their hygroscopic character; For this reason it is very diflicult to obtain the necessary uniform mixing of the nitrates with magnesium powder. The sulfates, it is true, are not hygroscopic, but naturally when in use, cause more smoke and smell and when mixed with the metals are sensitive to the moisture in the air when employed in the form of soluble salts.' Further, mixtures em loying the sulfates are diflicult toignite. these objections are avoided by employing insoluble combinations or combinations soluble h with difiiculty together with the heavy or other metal powder.

metal acids. These bodies form a fine powder which preserves its properties in the.

presence of air and which, as opposed to the nitrates, remains in powdered form either when kept apart or mixed with magnesium sulfates the mixture according to the present invention flashes withpractipally .no smoke Specification of Letters Patent. Application am June 29. Serial No. 440,995.

Even

As opposed to the Patented 4 m 20, 19 09.

or'sinell as only the heavy m'etal'oxid is left .behind' after combustion. 4

' The; most important 0f the known coin; pounds of thor um with heavy metal acids.

for the purpose'of the resent invention are the chromate and t e 'tungstate. -The.

chromate of thorium both the watercfill tflinilif aswell as in the water-free forin is specia suitable for, flash lights in consequence of its property of producing ,an extraordinarily energetic flash. .This property also distinguishes the chromate of thorium from the chromate of cerium which has also hitherto been proposed." When mixed with magnesium, powderthe chro-' mate of thorium fol-mean unalterable and v i with extraordinary d, reducesv an in tensel'y strong lightand is a most smokeless.

dufiable flash-lightffmi-xture which flashes The-mixtures-are also in spite'of their easy inflammabilit-y-"absol llt y sure against explosionshaking or and, thereby satisfy 7 the conditions "whichare necesi saigy forapfoducing a flash light powder-. Fonproducing a light 30 to 35 parts of magnesmmfpowderare'mixed with' Y parts of chromate-ofthotium;

When the heavy of vtheiacid radical of the thorium compoundused is, tungsten the corresponding tungstate of thorium produces arsomeivhat slower combustion and may therefore with advantage be used for time-light mixtures. A very g00dt-imelight mixture which is also free from smoke.

and produces a strong light is obtained by very effective flashing, while their propor-. 105

tionally small content of acid produces a combustion smell.

When precipitating the insoluble peroxid of thorium from solutions of thorium by means of peroxid of hydrogen it is known that when ammonia is not added at the practically without smoke and.

same time, apart, that is a fourth part,

and then rapidly cooling.

of the acid of the original normal salt,l separates out with the insoluble precipitate. I

The sulfate and the nitrate of such insoluble compounds of peroxid of thorium with.

acids are already well known and their production and properties have been described in detail, (see Cleve, Bull. Soc. Ohim. (2)

43.57 and \Vyrouboif and Verneuil, Com '6. 1 In consequenceof this;

Renal. 126, 341). general property of the precipitates of the peroxids of thorium to hold a part of the acid it will be readily understood that other 1 solutions of the salts of thorium may be similarly treated for the production of precipitates which have not yet been discussed} in technical literature, for example the chlorate or still better for the purposes of i the present invention the perchlorate on account of its smaller explosive properties.

As a matter of fact it 'is possible to obtain 1 a gelatin like perchlorate precipitate with the same propert es in a. manner analogous to the process described in the literature cited above for the production ofthe nitrate precipitate, that is to say by adding to a solutlon of hydroxid of thorium in perchloric acid an excess of peroxid of hydrogen heating the same to about (30 C. The precipitate of the perchlorate, like the nitrate precipi- -,tate, dries after sufiicient washing and at rapidly and easily mixed with the magne' sium ])O\\'Ll0l'.- From the above will be seen that the compound of perchloric acid with a metal of the rare earth is particularly suited 't'oapplication in the present invention as usually the normal per(':hlorate.- of the rare earths form into soapy hygroscopic masses.

A very good flash light mixture may be obtained by mixing); one part of magnesium powder withabout one part of the nitrate, sulfate or perchlorate precipitate of peroxid of thorium. l-or coloring the light or for prolonging the combustion or in any other 'ay influencing the properties of the mixtures other known bodies may be added. and it will also be understood that instead of magnesium. aluminum or an alkaline earth metal may be employed.

1. flash light composition comprising a combustible metal and' a non-hygroscopic and insoluble salt of a thorium oxid, substantially as described.

2. A flash light composition comprising a combustible metal and a non-hygroscopic and insoluble oxidizing salt consisting of an acid of a heavy metal combined with thorium. substantially as described.

A flash light composition comprising a (-ombustiblc metal and chromate of thorium.

In witness whereof I have hereunto set my hand in the presence of two witnesses.

. CARL BETHGE.

Witnesses I'IENRY HAsrnn, \VoLnuMAn HAUPT. 

